Benefits of Mullein Tea: What the Research Shows About This Traditional Herbal Remedy

Mullein (Verbascum thapsus) has been used in folk medicine for centuries — particularly for respiratory complaints — and today it shows up in herbal teas, tinctures, and supplements marketed for lung and throat support. But what does the available research actually say, and how much of the traditional use holds up to scientific scrutiny?

What Mullein Is and What It Contains

Mullein is a tall, flowering plant native to Europe and Asia, now widespread in North America. The large, soft leaves are most commonly used in herbal preparations, including teas, while the flowers are sometimes used in oil infusions.

The plant contains several bioactive compounds that researchers have studied for potential biological activity:

• Saponins — compounds associated with expectorant-like properties (helping loosen mucus)
• Mucilage — a gel-like substance that may coat and soothe mucous membranes
• Flavonoids — plant-based antioxidants including luteolin and apigenin
• Iridoid glycosides — compounds studied for anti-inflammatory properties in laboratory settings
• Verbascosaponin and aucubin — specific constituents that have drawn interest in preliminary research

The concentration of these compounds in a brewed tea depends on leaf quality, harvest timing, preparation method, and steeping time — all factors that can vary considerably between products and homemade preparations.

What the Research Generally Shows 🌿

It's important to be clear about the state of the evidence: most of the research on mullein is preliminary, consisting of laboratory (in vitro) studies and some animal research. Large, well-controlled human clinical trials are limited. That gap matters when evaluating the claimed benefits.

Respiratory Support

The most historically prominent use of mullein is for respiratory symptoms — coughs, bronchitis, and congestion. The mucilage content is thought to coat and soothe irritated throat and airway tissue, while saponins may support the loosening of mucus.

Some small studies and traditional medicine reviews support the idea that mullein has expectorant and demulcent properties, but robust clinical evidence from human trials is sparse. A frequently cited systematic review of herbal ear drops (which included mullein among other botanicals) showed some benefit for ear pain in children, though the contribution of mullein specifically was difficult to isolate.

Antimicrobial Properties

Laboratory studies have shown that mullein extracts demonstrate activity against certain bacteria and viruses in controlled settings — including some strains of Staphylococcus aureus and Klebsiella pneumoniae. These findings are in vitro, meaning they come from cell or petri dish studies, not human trials. What happens in a lab setting often behaves very differently inside the human body.

Anti-Inflammatory Activity

Flavonoids and iridoid glycosides in mullein have shown anti-inflammatory effects in laboratory and animal research. Whether these effects translate meaningfully to humans drinking mullein tea — at the concentrations typically achievable through a brewed cup — remains an open question.

Antioxidant Content

Mullein leaves contain flavonoids with antioxidant activity. Antioxidants help neutralize unstable molecules called free radicals in the body, and dietary antioxidants from plant sources are broadly associated with health benefits in nutrition research. Mullein tea may contribute modestly to antioxidant intake, though it is not a concentrated antioxidant source compared to many common foods and herbs.

Factors That Shape Individual Outcomes

Even setting aside the limited human clinical evidence, how a person responds to mullein tea depends on several variables:

One practical note: mullein leaves should be strained carefully before drinking. The fine leaf hairs can be irritating to the throat and mucous membranes if consumed in the liquid.

Who Has Traditionally Used Mullein — and What That Tells Us

Long-term traditional use across many cultures is sometimes cited as informal evidence of safety and utility. Native American groups, European herbalists, and Ayurvedic practitioners all have documented histories of using mullein for respiratory and inflammatory conditions. Traditional use is a legitimate starting point for scientific investigation — but it isn't a substitute for it.

Some researchers use ethnobotanical records to prioritize which herbs to study formally. Mullein is on that list, but the formal human research simply hasn't caught up to its reputation yet.

What Remains Uncertain 🔬

Several questions don't have clear answers from current research:

• Whether bioactive compounds survive brewing and are absorbed in meaningful quantities
• What amount of consumption, over what period, corresponds to any measurable effect in humans
• How mullein tea interacts with specific medications or health conditions at an individual level
• Whether commercial mullein tea products contain standardized amounts of key compounds

The gap between centuries of traditional use and modern clinical validation is real — and it's the reason that what applies to herbal medicine broadly, and mullein specifically, can look quite different depending on the standards of evidence being applied.

Your own health status, current medications, existing respiratory conditions, and dietary context are the variables that determine whether and how mullein tea fits into your larger picture — and those are the pieces this article can't assess for you.